The present disclosure relates generally to a control system for a building (e.g., a building HVAC system) or building management system. The present disclosure relates more particularly to a hybrid control system for a building with an adaptive user interface.
A hybrid control system combines the functionality of a discrete control system and a closed loop control system. A discrete control system can be described using a finite state diagram (FSD) and implemented in a finite state machine (FSM). In a discrete control system, a controller evaluates state transition conditions (e.g., using feedback from the controlled system) and transitions between various operating states when one or more of the state transition conditions are satisfied. Each of the operating states in a discrete control system can have a corresponding set of control outputs. In some embodiments, the control outputs in a discrete control system remain constant as long as the controller remains in the same operating state and change only when the controller transitions into a new operating state.
A closed loop control system can be implemented using any of a variety of control techniques (e.g., feedback control, feedforward control, extremum seeking control, proportional-integral control, proportional-integral-derivative control, model predictive control, etc.). In a closed loop control system, a controller modulates a control output (i.e., a manipulated variable) provided to the controlled system over a range of values in order to achieve a desired effect. For example, the controller can modulate the control output to drive a monitored variable to a setpoint. In some embodiments, the controller uses feedback from the controlled system to determine an error between the setpoint and the monitored variable. The controller can variably increase or decrease the control output within the range of values in order to drive the error to zero.
Some hybrid control systems operate in a manner that is easily understandable by a user. For example, a human operator observing the behavior of a simple hybrid control system can easily understand what the system is doing in each of the operating states and why the system is operating in the current operating state. However, it can be difficult for a user to understand the behavior of more complex systems with a greater number of operating states, especially when the state transition conditions are non-intuitive and the closed loop control techniques within the operating states are complicated.
Using conventional interfaces, it can be difficult for a user to understand what the control system is doing and why. For example, the information presented to the user often does not clearly indicate what the control system is doing in each of the operating states and/or why the control system is operating in the current operating state. As a result, some automatic control systems are often manually overridden or disabled because the human operator does not understand whether the system is operating properly. Such manual overrides can reduce system performance and lead to suboptimal operation. It would be desirable to provide a hybrid control system which communicates expected behaviors and explains system operation in a user-friendly manner.